Ni-doped Zinc Oxide Research Articles

Enhancement of structural, optical, electrical, optoelectronic and thermoelectric properties of ZnO thin film via Ni doping and Ni-B co-doping

In this study, the effects of nickel (Ni) and boron (B) elements on the structural, optical, electrical, optoelectronic, and thermoelectric properties of zinc oxide (ZnO) material were investigated. Therefore, undoped ZnO, 3% Ni-doped ZnO (Zn0.97Ni0.03O), and 3% Ni-1% B co-doped ZnO (Zn0.96Ni0.03B0.01O) solutions were prepared by the sol gel method. The produced solutions were coated on glass and p-type Si substrates via dip coating and spraying methods in the form of thin films. We produce pure and n-type semiconductors in the form of nanodots which have wurtzite ZnO polycrystalline structure for all samples. Ni and B co-doped sample is morphologically, electrically and optically enhanced the ZnO material with 3.08 eV band gap, homogenous surface and the highest electrical conductivity. In addition, the best material among the three samples that can be used as a visible light-sensitive sensor is Zn0.96Ni0.03B0.01O under feedback voltage. Technologically, this material can be turned into a photodiode device in the form of Au/Zn0.96Ni0.03B0.01O/p-Si. While the obtained ideality factor of ZnO from the forward bias region decreases from 5.7 to 3.4, its barrier height increases from 0.636 eV to 0.667 eV and serial resistance of contact decreases from 121.6 × 103 Ω to 5.6 × 103 Ω with Ni and B co-doping. Ni doping thin film improves the photovoltaic, and thermoelectric properties of ZnO. Ni-doped ZnO sample can be studied in form of the thin films as a thermoelectric material due to its ZT value is nearly 1.73 × 10–4 at 650 K. Its thermoelectric performance is 13 times better than the that of pure ZnO for the same temperature values. The efficiency of Ni-doped ZnO sample as solar cell increases 10 times compared to pure ZnO. In addition to the production of materials with improved energy efficiency, economical products suitable for use in large areas have been obtained in this study.

Effect of foreign impurity and growth temperatures on hexagonal structure and fundamental properties of ZnO nanorods.

This study examined the influence of growth temperature and dopant concentration on the properties of Gd- and Ni-doped zinc oxide nanorods (ZnO NRs). ZnO seed layers were deposited on glass substrates using a sol-gel and dip-coating approach. Gd- and Ni-doped ZnO NRs were hydrothermally grown on the seed layers at different temperatures such as 75, 90, and 105°C for a constant growth time of 5 h. The crystal structure, optical, surface morphology views, and electrical properties of the NRs were extensively investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy, and four probe experimental methods. The XRD analysis confirmed the successful substitution of Zn2+ ions by Gd3+ and Ni2+ within the ZnO main matrices. The reordering of hexagonal structures with varied electronegativity, ionic radius dimensions, and valence electron states of Gd and Ni dopants affected seriously the fundamental characteristic features of NRs. The SEM images showed that the ZnO NRs grown at 90°C possessed a more favorable surface morphology and well-defined hexagonal shape compared with those grown at other growth temperatures. Higher dopant concentration led to an increase in NR diameter but a decrease in density depending on the increase in the space between the NRs. Additionally, the optical transmittance was found to generally enhance with increasing dopant concentration. The results obtained highlighted the interplay between growth temperature, dopant type and concentration in tailoring the structural, morphological, and optical properties of Gd- and Ni-doped ZnO NRs, paving the way for the development of optimized nanomaterials for various applications. RESEARCH HIGHLIGHTS: The XRD analysis confirmed the successful substitution of Zn2+ ions by Gd3+ and Ni2+ within the ZnO main matrices. The SEM images showed that the ZnO NRs grown at 90°C possessed a more favorable surface morphology and well-defined hexagonal shape compared with those grown at other growth temperatures. The optical transmittance was found to generally enhance with increasing dopant concentration. The results obtained highlighted the interplay between growth temperature, dopant type and concentration in tailoring the structural, morphological, and optical properties of Gd- and Ni-doped ZnO NRs, paving the way for the development of optimized nanomaterials for various applications.

Degradation of rhodamine B dye under visible and solar light on zinc oxide and nickel-doped zinc oxide thin films

The kinetic investigation of rhodamine B dye's photocatalytic degradation, chosen as a model pollutant, was conducted at room temperature using Zinc oxide (ZnO) and nickel-doped zinc oxide (Zn0.97Ni0.03O) photocatalysts synthesized through the spray pyrolysis method. XRD analysis confirmed the formation of hexagonal ZnO and Zn0.97Ni0.03O films, with crystallite sizes ranging from 19 to 29 nm and varying in mean average grain size from 72 nm to 88 nm. The surface morphology of the Ni-doped ZnO films was influenced by nickel doping, observed through SEM and TEM micrographs, revealing a dense structure of spherical-shaped crystals. Light transmission and optical band gap energy of the films ranged between specified values, ranging from 3.27 to 3.24 eV. The degradation process was assessed under various conditions, including different light sources (UV lamp and solar irradiation), pH levels, and substrate concentrations. Degradation followed a pseudo-first-order kinetic model, with rate constants (k) and half-life times (t1/2) calculated accordingly. The degradation efficiency of undoped ZnO and ZnO doped with nickel decreased with increasing concentration under UV irradiation from (0.1–0.5 M) under UV irradiation decreased from (34.29–45.02) (49.61–56.61), while under visible light are (40–45.07 %) (58.46–60.24 %), removal rates ranged within specific percentages. The porous Zn0.97Ni0.03O synthesized at 0.5 M exhibited the highest photocatalytic efficiency due to its enhanced crystallinity, resulting in degradation rates of 9.22 and 11.22 × 10−3 min−1 and half-life times of 75.18 and 61.77 min at 90 min specified for both UV and solar light irradiations, respectively. Acidification of the reaction medium accelerated the photocatalytic degradation kinetics, while alkalization slowed it down. These findings mark a significant advancement in the utilization of oxide semiconductors for water pollutant degradation under natural sunlight.

Preparation and characterisation of pure and Ni doped ZnO nanorods

ABSTRACT One-dimensional pure and Ni-doped zinc oxide nanorods (NRs) were prepared by chemical bath technique. Some physical properties like optical, morphological and structural were examined for prepared NRs. The result of X-ray diffraction XRD was exposed that the crystal structure was hexagonal for both pure and Ni-doped NRs where there is no change in the crystal system but some small shifting in diffraction angle appeared. The chemical composition and the presence of Ni atoms in the ZnO were approved by EDX test. Additionally, morphology investigation of the scanning electron microscopy (SEM) is conducted and showed that the shape of prepared materials was NRs. A red shift in the absorption spectrum and band gap happened after doping with Ni where the energy gap dropped from 3.72 for ZnO to 3.5 eV for ZnO:Ni.

Towards a Highly Efficient ZnO Based Nanogenerator.

A nanogenerator (NG) is an energy harvester device that converts mechanical energy into electrical energy on a small scale by relying on physical changes. Piezoelectric semiconductor materials play a key role in producing high output power in piezoelectric nanogenerator. Low cost, reliability, deformation, and electrical and thermal properties are the main criteria for an excellent device. Typically, there are several main types of piezoelectric materials, zinc oxide (ZnO) nanorods, barium titanate (BaTiO3) and lead zirconate titanate (PZT). Among those candidate, ZnO nanorods have shown high performance features due to their unique characteristics, such as having a wide-bandgap semiconductor energy of 3.3 eV and the ability to produce more ordered and uniform structures. In addition, ZnO nanorods have generated considerable output power, mainly due to their elastic nanostructure, mechanical stability and appropriate bandgap. Apart from that, doping the ZnO nanorods and adding doping impurities into the bulk ZnO nanorods are shown to have an influence on device performance. Based on findings, Ni-doped ZnO nanorods are found to have higher output power and surface area compared to other doped. This paper discusses several techniques for the synthesis growth of ZnO nanorods. Findings show that the hydrothermal method is the most commonly used technique due to its low cost and straightforward process. This paper reveals that the growth of ZnO nanorods using the hydrothermal method has achieved a high power density of 9 µWcm-2.

Experimental and DFT study of structural and optical properties of Ni-doped ZnO nanofiber thin films for optoelectronic applications

As an important metal oxide semiconductor, transition metal-doped zinc oxide (ZnO) has attracted great interest for various applications in optoelectronic, spintronic photovoltaic and photodetectors due to its significant chemical and physical properties. In this research study, pure and nickel (Ni)-doped ZnO nanostructured films were synthesized via the sol-gel method using the spin coating technique on glass substrates. The structural results revealed that all samples exhibited a polycrystalline wurtzite structure and a (002) plane preferred orientation. The crystallite size was reduced by Ni doping. The morphology micrographs indicate that the surface of thin films shows nanofiber structures. An optical study revealed the high transparency of the films. The photoluminescence (PL) showed one ultraviolet (UV) emission at 387 nm and different defect emissions for all films. The absorption, band gap and PL emissions intensities were influenced by Ni doping. Ni-doped ZnO nanostructured thin films revealed high UV sensitivity and photoresponse. Therefore, these thin films are a promising material for a UV photodetector. The dielectric function, absorption coefficient and energy band gap were also calculated and discussed by density functional theory (DFT), using the Ultra Soft Pseudo Potential (US-PP) approach implemented in the CASTEP code.

ZnO and Ni-doped ZnO photocatalysts: Synthesis, characterization and improved visible light driven photocatalytic degradation of methylene blue

The nickel modified zinc oxide (ZnO) photocatalysts with nominal composition of Zn1-xNixO (x = 0.0–0.5) were synthesized by wet chemical approach. Optical studies were performed using Fourier transformed infrared (FTIR), electronic spectroscopy and X-ray diffraction (XRD) methods. Scanning electron microscopy (SEM) complimented with Energy Dispersive X-ray (EDX) was used to study the morphology and chemical composition of prepared photocatalysts. A significant hypsochromic shift has been observed with respect to un-doped ZnO nanocatalyst due to quantum confinement effect. Subsequently, the band gap has been tuned to the region of lower wavelength. X-ray results reveal that ZnO nanocatalyst are in hexagonal crystalline form. In addition, the effect of nickel impurity on photocatalytic activity of ZnO nanocatalysts in degradation of methylene blue (MB) was also investigated. Degradation results showed that the MB was degraded more effectively by Ni-doped ZnO photocatalysts due to large band gap under visible light irradiation.

Synthesis and Characterization of Ni-Doped ZnO Nanoparticles for CO2 Gas Sensing

In this research, we synthesised nickel (Ni)-doped zinc oxide (ZnO) nanoparticles (NZ) with various atomic ratios of [Ni]/[Zn], i.e., 0.02, 0.04 and 0.06 using a simple sol–gel method. The synthesized materials were examined by different techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) attached with energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The observed XRD results confirmed that all the prepared samples exhibited a hexagonal wurtzite structure with no additional secondary phases, confirming that Ni ions were successfully incorporated into the lattices of ZnO crystals. The average size of the synthesized nanoparticles is in the range of 30–80 nm, as was confirmed from the TEM observations. The synthesized Ni-doped ZnO nanoparticles were used as functional material to fabricate efficient CO2 gas sensors. The gas detection results demonstrated an improvement in the response of the Ni-doped ZnO sensor towards CO2 gas. The data obtained at 350 ˚C working temperature reveal that this sensor has a modest reaction to CO2. With increasing Ni doping, we noticed that the baseline and the dynamic responses rises. Based on the obtained results, a plausible sensing mechanism towards CO2 gas sensor based on Ni-doped ZnO nanoparticles is also proposed and presented in this paper.

Room temperature ferromagnetic behavior of nickel-doped zinc oxide dilute magnetic semiconductor for spintronics applications

Abstract The multifunctional zinc oxide (ZnO) nanoparticles were economically grown through a simple co-precipitation technique. Ni-doped (1, 3, and 5 wt%) ZnO nanoparticles were also grown to comprehend their influence on the ferromagnetic property of the ZnO, especially at room temperature. The structural and surface morphological features of the prepared nanoparticles were studied through X-ray diffraction (XRD) and Scanning electron microscopy (SEM) techniques, respectively. Diffused reflectance, Photoluminescence, and Fourier transform infrared spectroscopic analyses were also carried out to understand the consequence of Ni doping on the ZnO nanostructure. The secondary phase formations such as NiO and NiO2 elucidate the solid solubility limit of three percent of nickel in the ZnO matrix. Size-strain analysis was performed to evaluate the crystallite size and apparent strain values. An increase in the agglomeration of particles is evidenced by SEM micrographs with an increase in the Ni doping percentage. The bandgap measurements showed a redshift from 3.25 to 3.18 eV for the Ni-doped nanoparticles. Photoluminescence study reveals the existence of lattice defects including interstitials and vacancies in the synthesized nanostructures. The vibrating sample magnetometer studies divulge that 3% Ni-doped ZnO nanoparticles show an intense ferromagnetic property at room temperature. These experimental observations manifested that the Ni-doped ZnO nanoparticles are potential candidates for spintronics device applications.

Ni-Doped ZnO Thin Films: Deposition, Characterization and Photocatalytic Applications.

Root like structured Ni-doped zinc oxide [Zn(1-x)NixO (x = 0.09)] thin films were deposited on a non-conducting glass substrate by indigenously developed spray pyrolysis system at optimized substrate hotness of 573±5 K. Thus obtained Ni-doped ZnO thin films were characterized by UV-visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Atomic Force Microscopy (AFM). XRD result revealed that Ni-doped ZnO has a polycrystalline nature with a hexagonal wurtzite structure. For pure ZnO and Ni-doped ZnO thin films, the particle sizes were 60.9 and 53.3 nm while lattice strain values were 1.56×10-3 and 1.14×10-3, respectively. The film surface showed characteristic root-like structure as observed by the SEM. It was observed that the Ni-doped ZnO thin films were grown in high density along with more extent of branching as compared to pure ZnO thin films but retained the root-like morphologies, however, the branches were more-thinner and of shorter lengths. AFM analysis showed that the surface grains of the Ni-doped samples are homogeneous with less RMS roughness values compared with the undoped ZnO samples. The photocatalytic activity of the prepared thin films was evaluated by the degradation of methyl orange (MO) dye under UV light irradiation. Pure ZnO and Ni-doped ZnO thin films took 150 min and 100 min to degrade about 60% MO dye, respectively.

A New Surface Charge Neutralizing Nano-Adjuvant to Potentiate Polymyxins in Killing Mcr-1 Mediated Drug-Resistant Escherichia coli.

Resistance to polymyxins when treating multidrug-resistant (MDR) Gram-negative bacterial infections limit therapeutic options. Here, we report the synthesis of a nickel (Ni) doped Zinc oxide (NZO) combined with black phosphorus (BP) (NZB) nanocomposite and its synergistic action with polymyxin B (PolB) against polymyxin-resistant Escherichia coli harboring mobilized colistin resistance (mcr-1) gene. NZB and PolB combination therapy expressed a specific and strong synergy against Mcr-1 expressing E. coli cells. The underlying mechanism of the synergy is the charge neutralization of the E. coli cell surface by NZB, resulting in a more feasible incorporation of PolB to E. coli. The synergistic concentration of NZB with PolB was proved biocompatible. Thus, the NZB is the first biocompatible nano-adjuvant to polymyxins against polymyxin-resistant E. coli cells, recognizing the physical status of bacteria instead of known adjuvants targeting cellular gene products. Therefore, NZB has the potential to revive polymyxins as leading last-resort antibiotics to combat polymyxin-resistant Gram-negative bacterial infections.

Reducing p-type Schottky contact barrier in metal/ZnO heterostructure through Ni-doping

Large contact resistance at metal-substrate/ZnO heterostructure interfaces prevents achieving highly efficient device performance. Herein, we present a systematic study on the effect of Ni-doping in the reduction of the Schottky contact barrier at metal-substrate/ZnO heterostructure. To this end, Ni-doped zinc oxide (Ni:ZnO) thin films were deposited on glass substrate by a spray technique with different Ni-doping concentrations. X-ray Diffraction and Atomic Force Microscopy (AFM) measurements showed that Ni-doping enhances the surface uniformity as compared to the undoped-ZnO films and significantly decreases the roughness (RMS) from 35 to 17 nm. Conductive Atomic Force Microscopy (C-AFM) with a Bruker's platinum coated probe (Pt-Ir) tip results in the stabilization of a p-type Schottky contact with a small height barrier of ~0.4 eV, which is among the smallest values reported in literature for ZnO thin films. Our first principle calculations, which are based on the relative alignment of the band edges of the components, also confirm the reduction in the Schottky barrier height by Ni-doping in line with the experimental tendency. Both experimental and theoretical results provide a robust evidence of the potential of stabilization of a small p-type Schottky contact at metallic-substrate/ZnO interface through a Ni-doping.

SYNTHESIS, CHARACTERIZATION AND PHOTOCATALYTIC APPLICATIONS OF S-DOPED GRAPHITIC CARBON NITRIDE NANOCOMPOSITES WITH NICKEL DOPED ZINC OXIDE NANOPARTICLES

Coprecipitation method was adopted for the synthesis of undoped and Ni-doped zinc oxide nanoparticles. The photocatalytic activity of the synthesized particles was examined by degradation of methylene blue under UV bulb. The S-doped graphitic carbon nitride was obtained by calcination of thiourea and composites were formed with S-doped graphitic carbon nitride and nickel doped zinc oxide nanoparticles using liquid exfoliation method. The ethanol and water were used as solvents for the liquid exfoliation. The photocatalytic activity was performed under UV and visible light by using a UV-visible spectrophotometer with different concentrations of composites for the degradation of methylene blue. The doping of nickel on zinc oxide nanoparticles and formation of sulfur doped graphitic carbon nitride composites were confirmed by FTIR and XRD analyses. The FTIR analysis sowed a signal at 838cm-1 due to the presence of Ni-O bond. The peaks at 3649cm-1 and 3735cm-1 confirmed the presence of amide group. The shift in absorption maxima from 364nm to 376nm (red shift) in UV spectrum was a confirmation of increased Ni content. The different concentrations of composites showed great impact on the degradation of methylene blue.

Influence of Cu and Ni dopants on the sensing properties of ZnO gas sensor

In this work, the influence of Cu and Ni doping on the propane gas (C3H8) detection of zinc oxide (ZnO) samples was evaluated. Three powder samples: (a) pure ZnO, (b) Ni-doped ZnO, and (c) Cu-doped ZnO, were obtained by homogenous precipitation method. The Ni and Cu concentration was of 1 at.%. The X-ray diffractograms indicate that all samples showed a hexagonal wurtzite-type crystal structure. Micrographs obtained by scanning electron microscopy (SEM) show a spherical surface morphology typical of nanostructured materials in the pure ZnO and ZnO/Ni samples. The gas sensing devices were manufactured by pressing the powders in pellets form. The sensing response of all pellets was measured by the surface electrical resistance change in a propane (C3H8) atmosphere at concentrations from 0 to 500 ppm at different operation temperatures (100, 200, and 300 °C). ZnO/Cu pellet presented the highest resistance change, registered at 300 °C in a propane concentration of 500 ppm.

Investigation of in-vitro antibacterial and seed germination properties of green synthesized pure and nickel doped ZnO nanoparticles

A plant mediated, green and cost effective route was utilized for synthesis of pure and Ni-doped Zinc oxide nanoparticles (ZnO-NPs) using Brassica rapa leaf extract. Optical, structural and morphological properties of prepared nanoparticles were affirmed through UV–Vis spectroscopy, X-ray diffraction (XRD) and Scanning electron microscopy (SEM), respectively. The synthesized ZnO-NPs represented hexagonal phase with crystallite size of 27.48 nm and were irregular in shape. The existence of functional groups was explored using Fourier transform infrared spectroscopy. The antibacterial activity of the prepared nanoparticles was verified against a gram positive bacteria Micrococcus luteus and a gram negative bacteria Enterobacter aerogenes which confirmed that ZnO-NPs are efficient antibacterial agents. In addition, the prepared nanoparticles were applied on wheat and pearl millet seeds to investigate their effect on germination. It was observed that there was an appreciable enhancement in seed germination of seeds after treated with the synthesized ZnO-NPs.

Fabrication and Characterization of Ni-Doped ZnO Nanorod Arrays for UV Photodetector Application

In this work, the structure morphologies, lattices, and optical properties of zinc oxide (ZnO) nanorods (NRs) with various amounts of nickel (Ni) dopants were investigated and explored. The 100 nm ZnO seed layer was grown on the Corning glass substrate by the radio frequency (RF) magnetron sputtering technique, and the chemical bath deposition (CBD) method was used to grow NR arrays. It was found that the Ni concentration of the sample is 1.06 at% by EDX spectra examination. All the NRs exhibited a hexagonal wurtzite structure and preferentially grew along the c-axis on the substrate. Additionally, the ultraviolet (UV) photodetectors (PDs) with Ni-doped ZnO (NZO) NRs based on metal-semiconductor-metal (MSM) structure were fabricated through a photolithography process. Then, such a sample was annealed at 500 °C to obtain good performance and reduced oxygen vacancy (∼560 nm). The results showed that the NZO NRs were with an excellent photosensitivity for UV PD applications and a faster rise/decay time than pure ZnO. Furthermore, with a 3 V applied bias and 380 nm UV illumination, the sensitivities of the fabricated ZnO PDs with different Ni contents (0, 4, and 8 mM) were 71.45, 393.04, and 238.75, respectively.

Ni-doped ZnO nanocrystalline material for electrocatalytic oxygen reduction reaction

Less expensive catalyst is highly required for the ORR half-cell reactions in the fuel cell. From now, the progress of the less expensive, active, potential ORR catalysts are much needed for the fuel cell technology compared to expensive, less abundant Pt based materials. In our investigation, less expensive and easily abundant nickel (Ni) have been doped into the nanocrystalline ZnO architecture were synthesized for the use in ORR as electrocatalyst. Influence of nickel doping into nanocrystalline ZnO nanomaterials were investigated by Raman, Photoluminescence, FTIR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM). XRD results proved that, the material is pure crystalline after and before doping. In our synthesized procedure, there is no significant changes in the morphology after Ni doped ZnO. The PL results also supported the integration of Ni into zinc oxide (ZnO) nanoscale material, increasing the vacancy of the synthesized ZnO nanostructured materials. After successful formation of the Ni doped ZnO and without doped ZnO has shown the heightened electrocatalytic bustle. Nanostructured Ni doped ZnO has shown significant ORR activity in alkaline solution (0.1 M KOH). The enriched movement of the Ni doped ZnO indicates that the synthesized materials in our process can be utilised as the cheap and effective electrocatalyst in the ORR fuel cell reactions.

Preparation and Characterization of Transparent Conducting Mn and Ni-Doped Zinc Oxide Films Prepared by Successive Ionic Layer Adsorption and Reaction Method

This paper reported the preparation and characterization of transparent conducting oxide thin films. Undoped and doped ZnO thin films were prepared by SILAR method. The micro-structural and optical properties were investigated. X-ray diffraction patterns revealed that the prepared thin films are polycrystalline in nature and has a hexagonal structure. The micro-structural properties of prepared thin films were calculated and crystallite size tends to changes due to dopant. The texture coefficients have been evaluated and found to be greater than unity revealing high texturing of the film. Undoped and Mn-doped ZnO prefer the orientation of (002) but Ni-doped ZnO and Mn and Ni co-doped ZnO prefers (100) orientation. The transmittance spectra of pure and transition metal-doped films were plotted against UV-Vis-NIR region and found that the transmittance changes with dopant and nature of doping. The optical band gap values were found to be in the range of 3.00–3.39 eV. The optical constants such as extinction coefficient, refractive index, dielectric constant and optical conductivity were examined.

Antibacterial potential of Ni-doped zinc oxide nanostructure: comparatively more effective against Gram-negative bacteria including multi-drug resistant strains.

Infections by multidrug-resistant (MDR) bacteria are one of the most threatening concerns for public health. For this purpose, nanomaterials have emerged with great potential for antibacterial activity. In this paper, we report the synthesis of new Ni2+-doped zinc oxide (Ni-ZnO or NZO) nanostructures as targeted antibacterial agents for Gram-negative bacteria. A one-pot low-temperature solution process was used with varying compositions containing 2 or 5% Ni2+ relative to Zn2+, resulting in 2NZO or 5NZO, respectively. X-ray diffractometry, transmission electron microscopy, and X-ray photoelectron spectroscopy were used for material characterization. Further, the antibacterial activity against both Gram-negative [Escherichia coli (E. coli) and Acinetobacter baumannii (A. baumannii) strains including standard, MDR, and clinical isolates associated with mcr-1 gene] and Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) bacteria were evaluated through analysis of zone of inhibition, minimum inhibitory concentration (MIC), and scanning electron microscopy images. Among the prepared nanostructures, the 5NZO sample showed excellent antibacterial activity against MDR strains of A. baumannii and E. coli. In addition, samples of NZO generated approximately 7 to 16 times more reactive oxygen species (ROS) in E. coli compared to ZnO. Our synthesized nanomaterials have the potential to fight MDR and colistin-resistant Gram-negative bacteria.

Influence of Ni dopant on surface morphology of nanostructured ZnO thin films grown by SILAR method

ABSTRACT Pure and Nickel (Ni) doped zinc oxide (ZnO) thin films with different concentrations (1%, 3% and 5%) were fabricated using one of the simplest physical deposition processes called Successive Ionic Layer Adsorption and Reaction (SILAR) method. The physico-chemical properties of the fabricated ZnO and Ni-doped ZnO thin films were characterised using different analytical tools. The crystallise size of the fabricated films was determined from the X-ray Diffraction analysis. The presence of functional groups in the materials was confirmed from the Fourier-Transform Infrared analysis. The changes in the surface morphology and roughness of the films with respect to the addition of Ni dopant as well as an increase in dopant concentration were examined from Scanning Electron Microscopy and Atomic Force Microscope. The optical bandgap energy was determined from the UV-Visible spectrometer. The chemical state and the elemental composition were evaluated using X-ray Photoelectron Spectroscopy.